Use `unsigned int` instead of `int` Overflow for signed types is undefined behavior. Hence the compiler can trap when it happens and remain standards compliant

Use `unsigned int` instead of `int` Overflow for signed types is undefined behavior. Hence the compiler can trap when it happens and remain standards compliant. For unsigned types, overflow is defined behavior, and hence -ftrap will not trigger on overflow. An interesting flip side of this is that using signed types can be a lot faster because the compiler is allowed to assume that overflow will not happen, which lets it apply more optimizations.